1. Technical Field
The present invention generally relates to bobbins, and particularly to a bobbin used in an electromagnetic motor.
2. Description of Related Art
Electromagnetic motors are widely used in many industries. A bobbin is a critical component of an electromagnetic motor, so the design of the bobbin is very important.
Referring to FIG. 3, a typical bobbin 30 used in an electromagnetic motor (not shown) includes a rectangular bobbin body 31 and two sidewalls 33. The two sidewalls are formed at opposite ends (not shown) of the bobbin body, respectively. Each sidewall 33 protrudes radially outward to prevent wires (not shown) wound around the bobbin body 31 from sliding out. However, when the sidewalls 33 of the bobbin 30 are molded, additional side sliding blocks are required in the molds. Thus, the sidewalls 33 of the bobbin 30 cannot be molded in an up-down stripping manner, complicating the molding of the bobbin 30.
Referring to FIG. 4, another typical bobbin 40 includes a bobbin body 41 and two sidewalls 43. The bobbin 40 is similar to the bobbin 30 in FIG. 3 except that the sidewalls 43 protrude radially outward only at two opposite sides of the bobbin body 41. There is no overlap area between the sidewalls 43 at the top end of the bobbin body 41 and the sidewalls 43 at the bottom end of the bobbin body 41 along an axial direction of the bobbin body 41. This design enables the sidewalls 43 of the bobbin 40 to be molded in the up-down stripping manner. However, the wires wound around the bobbin body 41 may easily slide out from the bobbin body 41, where there are no sidewalls 43, and negatively affecting the quality of the bobbin 40.
Therefore, an improved bobbin which can be easily molded and prevent wires wound around the bobbin from sliding out is desired to overcome the above-described deficiencies.